Cancellation of Infrared Divergences in Hadronic Annihilation Decays of Heavy Quarkonia

In the framework of a newly developed factorization formalism which is based on NRQCD, explicit cancellations are shown for the infrared divergences that appeared in the previously calculated hadronic annihilation decay rates of P-wave and D-wave heavy quarkonia. We extend them to a more general case that to leading order in $v^2$ and next-to-leading order in $\alpha_s$, the infrared divergences in the annihilation amplitudes of color-singlet $Q\bar{Q}(^{2S+1}L_J)$ pair can be removed by including the contributions of color-octet operators $Q\bar{Q}(^{2S+1}(L-1)_{J'})$, $Q\bar{Q}(^{2S+1}(L-3)_{J''})$, ... in NRQCD. We also give the decay widths of $^3D_J\rightarrow LH$ at leading order in $\alpha_s$.Comment: 8 pages, LaTex(3 figures included), to be publishe

QCD Radiative Corrections to the Leptonic Decay Rate of the B_c Meson

The QCD radiative corrections to the leptonic decay rate of the $B_c$ meson are calculated using the formalism of nonrelativistic QCD (NRQCD) to separate short-distance and long-distance effects. The $B_c$ decay constant is factored into a sum of NRQCD matrix elements each multiplied by a short-distance coefficient. The short-distance coefficient for the leading matrix element is calculated to order $\alpha_s$ by matching a perturbative calculation in full QCD with the corresponding perturbative calculation in NRQCD. This short-distance correction decreases the leptonic decay rate by approximately $15\%$.Comment: Changed Eq. 2 to read 1/(8 \pi), put in a missing i M_{B_c} in Eq. 18, and put in a normalisation factor of 2 M_{B_c} in Eq. 19

A Comparison Of A Validated Otolith Method To Age Weakfish, Cynoscion-Regalis, With The Traditional Scale Method

Otoliths, scales, dorsal spines, and pectoral-fin rays were compared to ascertain the best hardpart for determining the age of weakfish, Cynoscion regalis. Each showed concentric marks, which could be interpreted as annuli. Sectioned otoliths, however, consistently showed the clearest marks, had 100% agreement between and within readers, and were validated by the marginal increment method for ages 1-5. This validated method of ageing weakfish was then compared with the traditionally used scale method. The scale method was less precise, as demonstrated by lower percent agreement, and generally assigned younger ages for fish older than age 6 (as determined by otoliths). Consequently, mean sizes at age based on scales showed no clear signs of an asymptote, whereas those based on otoliths did. Otolith annuli formed in April and May, whereas scale annulus formation was more variable, ranging from April to August. This extended time of annulus formation made scales poorly suited for back calculation

Maturity, Spawning, And Ovarian Cycle Of Atlantic Croaker, Micropogonias-Undulatus, In The Chesapeake Bay And Adjacent Coastal Waters

The reproductive biology of Atlantic croaker, Micropogonias undulatus, collected during 1990-91 from commercial catches in Chesapeake Bay and in Virginia and North Carolina coastal waters (n=3,091), was studied by using macroscopic and microscopic gonad staging, the gonadosomatic index, oocyte diameter distributions, and histological analysis. Atlantic croaker are multiple spawners with asynchronous oocyte development and indeterminate fecundity. Mean length at first maturity for males and females was 182 and 173 mm TL, respectively. More than 85% of both sexes were mature by the end of their first year and all were mature by age 2. Spawning extends over a protracted period (July-December), but individual fish apparently spawn over a shorter interval. Eleven gravid and running-ripe females were collected within the Chesapeake Bay suggesting some spawning occurs in estuarine waters. Monthly sex ratios indicated a strong predominance of females during the main period of spawning. A high incidence of atretic, advanced yolked oocytes in spawning females collected throughout the spawning season suggests that a surplus production of yolked oocytes may be part of the reproductive strategy of Atlantic croaker

Age And Growth Of Weakfish, Cynoscion Regalis, In The Chesapeake Bay-Region With A Discussion Of Historical Changes In Maximum Size

Weakfish, Cynoscion regalis, were collected in 1989-93 from commercial catches in the Chesapeake Bay region, and special collections of large fish were made in Delaware Bay. Ages were based on sectioned otoliths. Most weakfish were 200-600 mm TL and ages 1-4 years. Maximum age was 17 years from a 1985 Delaware Bay fish. Maximum current observed ages were 12 years in Chesapeake Bay and 11 years in Delaware Bay. However, fish older than age 6 were rare in both areas. There was no evidence that Delaware Bay fish reached a larger maximum size or maximum age than Chesapeake Bay fish. Although weakfish size was a poor predictor of age, weakfish growth was well described by the von Bertalanffy growth model (r(2)=0.98, n=854). Maximum size and age has fluctuated in both Chesapeake and Delaware Bays over the past thirty years. In both areas the maximum size of fish, based on citation records, greatly increased from the late 1960\u27s until the mid-1980\u27s, as did the numbers of these large fish. These fluctuations appear to be due to a series of strong year classes, beginning in the late 1960\u27s

Phenomenological Issues in Supersymmetry with Non-holomorphic Soft Breaking

We present a through discussion of motivations for and phenomenological issues in supersymmetric models with minimal matter content and non-holomorphic soft-breaking terms. Using the unification of the gauge couplings and assuming SUSY is broken with non-standard soft terms, we provide semi-analytic solutions of the RGEs for low and high choices of tan\beta which can be used to study the phenomenology in detail. We also present a generic form of RGIs in mSUGRA framework which can be used to derive new relations in addition to those existing in the literature. Our results are mostly presented with respect to the conventional minimal supersymmetric model for ease of comparison.Comment: 34 page

Minimal Flavour Violation with hierarchical squark masses

In a supersymmetric model with hierarchical squark masses we analyze a pattern of flavour symmetry breaking centered on the special role of the top Yukawa coupling and, by extension, of the full Yukawa couplings for the up-type quarks. For sufficiently heavy squarks of the first and second generation this leads to effective Minimal Flavour Violation of the Flavour Changing Neutral Current amplitudes. For this to happen we determine the bounds on the masses of the heavy squarks with QCD corrections taken into account, properly including previously neglected effects. We believe that the view presented in this paper altogether strengthens the case for hierarchical sfermions.Comment: 13 pages, 1 figure. v2: an equation correcte

Nucleon-nucleus optical potential in the particle-hole approach

Feshbach's projection formalism in the particle-hole model space leads to a microscopic description of scattering in terms of the many-body self-energy. To investigate the feasibility of this approach, an optical potential for O-16 is constructed starting from two previous calculations of the self-energy for this nucleus. The results reproduce the background phase shifts for positive parity waves and the resonances beyond the mean field. The latter can be computed microscopically for energies of astrophysical interest using Green's function theory.Comment: 8 pages, 6 figures. Submitted to Phys. Rev.